cadmus_core/view/home/

mod.rs

mod address_bar;
mod book;
mod bottom_bar;
pub mod directories_bar;
mod directory;
mod library_label;
mod shelf;

use self::address_bar::AddressBar;
use self::bottom_bar::BottomBar;
use self::shelf::Shelf;
use super::top_bar::{TopBar, TopBarVariant};
use crate::color::BLACK;
use crate::context::Context;
use crate::device::CURRENT_DEVICE;
use crate::font::Fonts;
use crate::framebuffer::{Framebuffer, UpdateMode};
use crate::geom::{halves, CycleDir, DiagDir, Dir, Rectangle};
use crate::gesture::GestureEvent;
use crate::input::{ButtonCode, ButtonStatus, DeviceEvent};
use crate::library::Library;
use crate::metadata::{sort, BookQuery, Info, Metadata, SimpleStatus, SortMethod};
use crate::settings::{FirstColumn, Hook, LibraryMode, SecondColumn};
use crate::unit::scale_by_dpi;
use crate::view::common::{locate, locate_by_id, rlocate};
use crate::view::common::{toggle_battery_menu, toggle_clock_menu, toggle_main_menu};
use crate::view::filler::Filler;
use crate::view::keyboard::Keyboard;
use crate::view::menu::{Menu, MenuKind};
use crate::view::menu_entry::MenuEntry;
use crate::view::named_input::NamedInput;
use crate::view::navigation::providers::directory::DirectoryNavigationProvider;
use crate::view::navigation::StackNavigationBar;
use crate::view::notification::Notification;
use crate::view::search_bar::SearchBar;
use crate::view::{Bus, Event, Hub, RenderData, RenderQueue, View};
use crate::view::{EntryId, EntryKind, Id, ViewId, ID_FEEDER};
use crate::view::{BIG_BAR_HEIGHT, SMALL_BAR_HEIGHT, THICKNESS_MEDIUM};
use anyhow::{format_err, Error};
use fxhash::FxHashMap;
use rand_core::Rng;
use serde_json::{json, Value as JsonValue};
use std::fs;
use std::io::Write;
use std::io::{BufRead, BufReader};
use std::mem;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::thread;
use tracing::error;

pub const TRASH_DIRNAME: &str = ".trash";

pub struct Home {
    id: Id,
    rect: Rectangle,
    children: Vec<Box<dyn View>>,
    current_page: usize,
    pages_count: usize,
    shelf_index: usize,
    focus: Option<ViewId>,
    query: Option<BookQuery>,
    sort_method: SortMethod,
    reverse_order: bool,
    visible_books: Metadata,
    current_directory: PathBuf,
    target_document: Option<PathBuf>,
    background_fetchers: FxHashMap<u32, Fetcher>,
}

struct Fetcher {
    path: PathBuf,
    full_path: PathBuf,
    process: Child,
    sort_method: Option<SortMethod>,
    first_column: Option<FirstColumn>,
    second_column: Option<SecondColumn>,
}

impl Home {
    pub fn new(
        rect: Rectangle,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) -> Result<Home, Error> {
        let id = ID_FEEDER.next();
        let dpi = CURRENT_DEVICE.dpi;
        let mut children = Vec::new();

        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let (small_thickness, big_thickness) = halves(thickness);
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );

        let selected_library = context.settings.selected_library;
        let library_settings = &context.settings.libraries[selected_library];

        let current_directory = context.library.home.clone();
        let sort_method = library_settings.sort_method;
        let reverse_order = sort_method.reverse_order();

        context.library.sort(sort_method, reverse_order);

        let (visible_books, dirs) = context.library.list(&current_directory, None, false);
        let count = visible_books.len();
        let current_page = 0;
        let mut shelf_index = 2;

        let top_bar = TopBar::new(
            rect![
                rect.min.x,
                rect.min.y,
                rect.max.x,
                rect.min.y + small_height - small_thickness
            ],
            TopBarVariant::Search(Event::Toggle(ViewId::SearchBar)),
            sort_method.title(),
            context,
        );
        children.push(Box::new(top_bar) as Box<dyn View>);

        let separator = Filler::new(
            rect![
                rect.min.x,
                rect.min.y + small_height - small_thickness,
                rect.max.x,
                rect.min.y + small_height + big_thickness
            ],
            BLACK,
        );
        children.push(Box::new(separator) as Box<dyn View>);

        let mut y_start = rect.min.y + small_height + big_thickness;

        if context.settings.home.address_bar {
            let addr_bar = AddressBar::new(
                rect![
                    rect.min.x,
                    y_start,
                    rect.max.x,
                    y_start + small_height - thickness
                ],
                current_directory.to_string_lossy(),
                context,
            );
            children.push(Box::new(addr_bar) as Box<dyn View>);
            y_start += small_height - thickness;

            let separator = Filler::new(
                rect![rect.min.x, y_start, rect.max.x, y_start + thickness],
                BLACK,
            );
            children.push(Box::new(separator) as Box<dyn View>);
            y_start += thickness;
            shelf_index += 2;
        }

        if context.settings.home.navigation_bar {
            let provider = DirectoryNavigationProvider;
            let mut nav_bar = StackNavigationBar::new(
                rect![
                    rect.min.x,
                    y_start,
                    rect.max.x,
                    y_start + small_height - thickness
                ],
                rect.max.y - small_height - big_height - small_thickness,
                context.settings.home.max_levels,
                provider,
                current_directory.clone(),
            );

            nav_bar.set_selected(current_directory.clone(), &mut RenderQueue::new(), context);
            y_start = nav_bar.rect().max.y;

            children.push(Box::new(nav_bar) as Box<dyn View>);

            let separator = Filler::new(
                rect![rect.min.x, y_start, rect.max.x, y_start + thickness],
                BLACK,
            );
            children.push(Box::new(separator) as Box<dyn View>);
            y_start += thickness;
            shelf_index += 2;
        }

        let selected_library = context.settings.selected_library;
        let library_settings = &context.settings.libraries[selected_library];

        let mut shelf = Shelf::new(
            rect![
                rect.min.x,
                y_start,
                rect.max.x,
                rect.max.y - small_height - small_thickness
            ],
            library_settings.first_column,
            library_settings.second_column,
            library_settings.thumbnail_previews,
        );

        let max_lines = shelf.max_lines;
        let pages_count = (visible_books.len() as f32 / max_lines as f32).ceil() as usize;
        let index_lower = current_page * max_lines;
        let index_upper = (index_lower + max_lines).min(visible_books.len());

        shelf.update(
            &visible_books[index_lower..index_upper],
            hub,
            &mut RenderQueue::new(),
            context,
        );

        children.push(Box::new(shelf) as Box<dyn View>);

        let separator = Filler::new(
            rect![
                rect.min.x,
                rect.max.y - small_height - small_thickness,
                rect.max.x,
                rect.max.y - small_height + big_thickness
            ],
            BLACK,
        );
        children.push(Box::new(separator) as Box<dyn View>);

        let bottom_bar = BottomBar::new(
            rect![
                rect.min.x,
                rect.max.y - small_height + big_thickness,
                rect.max.x,
                rect.max.y
            ],
            current_page,
            pages_count,
            &library_settings.name,
            count,
            false,
        );
        children.push(Box::new(bottom_bar) as Box<dyn View>);

        rq.add(RenderData::new(id, rect, UpdateMode::Full));

        Ok(Home {
            id,
            rect,
            children,
            current_page,
            pages_count,
            shelf_index,
            focus: None,
            query: None,
            sort_method,
            reverse_order,
            visible_books,
            current_directory,
            target_document: None,
            background_fetchers: FxHashMap::default(),
        })
    }

    fn select_directory(
        &mut self,
        path: &Path,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if self.current_directory == path {
            return;
        }

        let old_path = mem::replace(&mut self.current_directory, path.to_path_buf());
        self.terminate_fetchers(&old_path, true, hub, context);

        let selected_library = context.settings.selected_library;
        for hook in &context.settings.libraries[selected_library].hooks {
            if context.library.home.join(&hook.path) == path {
                self.insert_fetcher(hook, hub, context);
            }
        }

        let (files, dirs) =
            context
                .library
                .list(&self.current_directory, self.query.as_ref(), false);
        self.visible_books = files;
        self.current_page = 0;

        let mut index = 2;

        if context.settings.home.address_bar {
            let addr_bar = self.children[index]
                .as_mut()
                .downcast_mut::<AddressBar>()
                .unwrap();
            addr_bar.set_text(self.current_directory.to_string_lossy(), rq, context);
            index += 2;
        }

        if context.settings.home.navigation_bar {
            let nav_bar = self.children[index]
                .as_mut()
                .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                .unwrap();
            nav_bar.set_selected(self.current_directory.clone(), rq, context);
            self.adjust_shelf_top_edge();
            rq.add(RenderData::new(
                self.child(index + 1).id(),
                *self.child(index + 1).rect(),
                UpdateMode::Partial,
            ));
            rq.add(RenderData::new(
                self.child(index).id(),
                *self.child(index).rect(),
                UpdateMode::Partial,
            ));
        }

        self.update_shelf(true, hub, rq, context);
        self.update_bottom_bar(rq, context);
    }

    fn adjust_shelf_top_edge(&mut self) {
        let separator_index = self.shelf_index - 1;
        let shelf_index = self.shelf_index;

        let target_separator_min_y = if let Some(nav_bar_index) =
            locate::<StackNavigationBar<DirectoryNavigationProvider>>(self)
        {
            self.children[nav_bar_index].rect().max.y
        } else {
            self.children[separator_index].rect().min.y
        };
        let current_separator_min_y = self.children[separator_index].rect().min.y;
        let y_shift = target_separator_min_y - current_separator_min_y;

        *self.children[separator_index].rect_mut() += pt!(0, y_shift);
        self.children[shelf_index].rect_mut().min.y = self.children[separator_index].rect().max.y;
    }

    fn toggle_select_directory(
        &mut self,
        path: &Path,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if self.current_directory.starts_with(path) {
            if let Some(parent) = path.parent() {
                self.select_directory(parent, hub, rq, context);
            }
        } else {
            self.select_directory(path, hub, rq, context);
        }
    }

    fn go_to_page(&mut self, index: usize, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        if index >= self.pages_count {
            return;
        }
        self.current_page = index;
        self.update_shelf(false, hub, rq, context);
        self.update_bottom_bar(rq, context);
    }

    fn go_to_neighbor(
        &mut self,
        dir: CycleDir,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        match dir {
            CycleDir::Next if self.current_page < self.pages_count.saturating_sub(1) => {
                self.current_page += 1;
            }
            CycleDir::Previous if self.current_page > 0 => {
                self.current_page -= 1;
            }
            _ => return,
        }

        self.update_shelf(false, hub, rq, context);
        self.update_bottom_bar(rq, context);
    }

    fn go_to_status_change(
        &mut self,
        dir: CycleDir,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if self.pages_count < 2 {
            return;
        }

        let max_lines = self.children[self.shelf_index]
            .as_ref()
            .downcast_ref::<Shelf>()
            .unwrap()
            .max_lines;
        let index_lower = self.current_page * max_lines;
        let index_upper = (index_lower + max_lines).min(self.visible_books.len());
        let book_index = match dir {
            CycleDir::Next => index_upper.saturating_sub(1),
            CycleDir::Previous => index_lower,
        };
        let status = self.visible_books[book_index].simple_status();

        let page = match dir {
            CycleDir::Next => self.visible_books[book_index + 1..]
                .iter()
                .position(|info| info.simple_status() != status)
                .map(|delta| self.current_page + 1 + delta / max_lines),
            CycleDir::Previous => self.visible_books[..book_index]
                .iter()
                .rev()
                .position(|info| info.simple_status() != status)
                .map(|delta| self.current_page - 1 - delta / max_lines),
        };

        if let Some(page) = page {
            self.current_page = page;
            self.update_shelf(false, hub, rq, context);
            self.update_bottom_bar(rq, context);
        }
    }

    // NOTE: This function assumes that the shelf wasn't resized.
    fn refresh_visibles(
        &mut self,
        update: bool,
        reset_page: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let (files, _) = context
            .library
            .list(&self.current_directory, self.query.as_ref(), false);
        self.visible_books = files;

        let max_lines = {
            let shelf = self
                .child(self.shelf_index)
                .downcast_ref::<Shelf>()
                .unwrap();
            shelf.max_lines
        };

        self.pages_count = (self.visible_books.len() as f32 / max_lines as f32).ceil() as usize;

        if reset_page {
            self.current_page = 0;
        } else if self.current_page >= self.pages_count {
            self.current_page = self.pages_count.saturating_sub(1);
        }

        if update {
            self.update_shelf(false, hub, rq, context);
            self.update_bottom_bar(rq, context);
        }
    }

    fn update_first_column(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        let selected_library = context.settings.selected_library;
        self.children[self.shelf_index]
            .as_mut()
            .downcast_mut::<Shelf>()
            .unwrap()
            .set_first_column(context.settings.libraries[selected_library].first_column);
        self.update_shelf(false, hub, rq, context);
    }

    fn update_second_column(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        let selected_library = context.settings.selected_library;
        self.children[self.shelf_index]
            .as_mut()
            .downcast_mut::<Shelf>()
            .unwrap()
            .set_second_column(context.settings.libraries[selected_library].second_column);
        self.update_shelf(false, hub, rq, context);
    }

    fn update_thumbnail_previews(
        &mut self,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let selected_library = context.settings.selected_library;
        self.children[self.shelf_index]
            .as_mut()
            .downcast_mut::<Shelf>()
            .unwrap()
            .set_thumbnail_previews(
                context.settings.libraries[selected_library].thumbnail_previews,
            );
        self.update_shelf(false, hub, rq, context);
    }

    fn update_shelf(
        &mut self,
        was_resized: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let dpi = CURRENT_DEVICE.dpi;
        let big_height = scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32;
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let shelf = self.children[self.shelf_index]
            .as_mut()
            .downcast_mut::<Shelf>()
            .unwrap();
        let max_lines = ((shelf.rect.height() as i32 + thickness) / big_height) as usize;

        if was_resized {
            let page_position = if self.visible_books.is_empty() {
                0.0
            } else {
                self.current_page as f32
                    * (shelf.max_lines as f32 / self.visible_books.len() as f32)
            };

            let mut page_guess = page_position * self.visible_books.len() as f32 / max_lines as f32;
            let page_ceil = page_guess.ceil();

            if (page_ceil - page_guess).abs() < f32::EPSILON {
                page_guess = page_ceil;
            }

            self.pages_count = (self.visible_books.len() as f32 / max_lines as f32).ceil() as usize;
            self.current_page = (page_guess as usize).min(self.pages_count.saturating_sub(1));
        }

        let index_lower = self.current_page * max_lines;
        let index_upper = (index_lower + max_lines).min(self.visible_books.len());

        shelf.update(
            &self.visible_books[index_lower..index_upper],
            hub,
            rq,
            context,
        );
    }

    fn update_top_bar(&mut self, search_visible: bool, rq: &mut RenderQueue) {
        if let Some(index) = locate::<TopBar>(self) {
            let top_bar = self.children[index]
                .as_mut()
                .downcast_mut::<TopBar>()
                .unwrap();
            let name = if search_visible { "back" } else { "search" };
            top_bar.update_root_icon(name, rq);
            top_bar.update_title_label(&self.sort_method.title(), rq);
        }
    }

    fn update_bottom_bar(&mut self, rq: &mut RenderQueue, context: &Context) {
        if let Some(index) = rlocate::<BottomBar>(self) {
            let bottom_bar = self.children[index]
                .as_mut()
                .downcast_mut::<BottomBar>()
                .unwrap();
            let filter = self.query.is_some() || self.current_directory != context.library.home;
            let selected_library = context.settings.selected_library;
            let library_settings = &context.settings.libraries[selected_library];
            bottom_bar.update_library_label(
                &library_settings.name,
                self.visible_books.len(),
                filter,
                rq,
            );
            bottom_bar.update_page_label(self.current_page, self.pages_count, rq);
            bottom_bar.update_icons(self.current_page, self.pages_count, rq);
        }
    }

    fn toggle_keyboard(
        &mut self,
        enable: bool,
        update: bool,
        id: Option<ViewId>,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let dpi = CURRENT_DEVICE.dpi;
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let (small_thickness, big_thickness) = halves(thickness);
        let has_search_bar = self.children[self.shelf_index + 2].is::<SearchBar>();

        if let Some(index) = rlocate::<Keyboard>(self) {
            if enable {
                return;
            }

            let y_min = self.child(self.shelf_index + 1).rect().min.y;
            let mut rect = *self.child(index).rect();
            rect.absorb(self.child(index - 1).rect());

            self.children.drain(index - 1..=index);

            let delta_y = rect.height() as i32;

            if has_search_bar {
                for i in self.shelf_index + 1..=self.shelf_index + 2 {
                    let shifted_rect = *self.child(i).rect() + pt!(0, delta_y);
                    self.child_mut(i).resize(shifted_rect, hub, rq, context);
                }
            }

            context.kb_rect = Rectangle::default();
            hub.send(Event::Focus(None)).ok();
            if update {
                let rect = rect![self.rect.min.x, y_min, self.rect.max.x, y_min + delta_y];
                rq.add(RenderData::expose(rect, UpdateMode::Gui));
            }
        } else {
            if !enable {
                return;
            }

            let index = rlocate::<BottomBar>(self).unwrap() - 1;
            let mut kb_rect = rect![
                self.rect.min.x,
                self.rect.max.y - (small_height + 3 * big_height) as i32 + big_thickness,
                self.rect.max.x,
                self.rect.max.y - small_height - small_thickness
            ];

            let number = matches!(id, Some(ViewId::GoToPageInput));
            let keyboard = Keyboard::new(&mut kb_rect, number, context);
            self.children
                .insert(index, Box::new(keyboard) as Box<dyn View>);

            let separator = Filler::new(
                rect![
                    self.rect.min.x,
                    kb_rect.min.y - thickness,
                    self.rect.max.x,
                    kb_rect.min.y
                ],
                BLACK,
            );
            self.children
                .insert(index, Box::new(separator) as Box<dyn View>);

            let delta_y = kb_rect.height() as i32 + thickness;

            if has_search_bar {
                for i in self.shelf_index + 1..=self.shelf_index + 2 {
                    let shifted_rect = *self.child(i).rect() + pt!(0, -delta_y);
                    self.child_mut(i).resize(shifted_rect, hub, rq, context);
                }
            }
        }

        if update {
            if enable {
                if has_search_bar {
                    for i in self.shelf_index + 1..=self.shelf_index + 4 {
                        let update_mode = if (i - self.shelf_index) == 1 {
                            UpdateMode::Partial
                        } else {
                            UpdateMode::Gui
                        };
                        rq.add(RenderData::new(
                            self.child(i).id(),
                            *self.child(i).rect(),
                            update_mode,
                        ));
                    }
                } else {
                    for i in self.shelf_index + 1..=self.shelf_index + 2 {
                        rq.add(RenderData::new(
                            self.child(i).id(),
                            *self.child(i).rect(),
                            UpdateMode::Gui,
                        ));
                    }
                }
            } else if has_search_bar {
                for i in self.shelf_index + 1..=self.shelf_index + 2 {
                    rq.add(RenderData::new(
                        self.child(i).id(),
                        *self.child(i).rect(),
                        UpdateMode::Gui,
                    ));
                }
            }
        }
    }

    fn toggle_address_bar(
        &mut self,
        enable: Option<bool>,
        update: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let dpi = CURRENT_DEVICE.dpi;
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;

        if let Some(index) = locate::<AddressBar>(self) {
            if let Some(true) = enable {
                return;
            }

            if let Some(ViewId::AddressBarInput) = self.focus {
                self.toggle_keyboard(
                    false,
                    false,
                    Some(ViewId::AddressBarInput),
                    hub,
                    rq,
                    context,
                );
            }

            // Remove the address bar and its separator.
            self.children.drain(index..=index + 1);
            self.shelf_index -= 2;
            context.settings.home.address_bar = false;

            // Move the navigation bar up.
            if context.settings.home.navigation_bar {
                let nav_bar = self.children[self.shelf_index - 2]
                    .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                    .unwrap();
                nav_bar.shift(pt!(0, -small_height));
            }

            // Move the separator above the shelf up.
            *self.children[self.shelf_index - 1].rect_mut() += pt!(0, -small_height);

            // Move the shelf's top edge up.
            self.children[self.shelf_index].rect_mut().min.y -= small_height;

            if context.settings.home.navigation_bar {
                self.adjust_shelf_top_edge();
            }
        } else {
            if let Some(false) = enable {
                return;
            }

            let sp_rect = *self.child(1).rect() + pt!(0, small_height);

            let separator = Filler::new(sp_rect, BLACK);
            self.children
                .insert(2, Box::new(separator) as Box<dyn View>);

            let addr_bar = AddressBar::new(
                rect![
                    self.rect.min.x,
                    sp_rect.min.y - small_height + thickness,
                    self.rect.max.x,
                    sp_rect.min.y
                ],
                self.current_directory.to_string_lossy(),
                context,
            );
            self.children.insert(2, Box::new(addr_bar) as Box<dyn View>);

            self.shelf_index += 2;
            context.settings.home.address_bar = true;

            // Move the separator above the shelf down.
            *self.children[self.shelf_index - 1].rect_mut() += pt!(0, small_height);

            // Move the shelf's top edge down.
            self.children[self.shelf_index].rect_mut().min.y += small_height;

            if context.settings.home.navigation_bar {
                let rect = *self.children[self.shelf_index].rect();
                let y_shift = rect.height() as i32 - (big_height - thickness);
                let nav_bar = self.children[self.shelf_index - 2]
                    .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                    .unwrap();
                // Move the navigation bar down.
                nav_bar.shift(pt!(0, small_height));

                // Shrink the nav bar.
                if y_shift < 0 {
                    let y_shift = nav_bar.shrink(y_shift, &mut context.fonts);
                    self.children[self.shelf_index].rect_mut().min.y += y_shift;
                    *self.children[self.shelf_index - 1].rect_mut() += pt!(0, y_shift);
                }

                self.adjust_shelf_top_edge();
            }
        }

        if update {
            for i in 2..self.shelf_index {
                rq.add(RenderData::new(
                    self.child(i).id(),
                    *self.child(i).rect(),
                    UpdateMode::Gui,
                ));
            }

            self.update_shelf(true, hub, rq, context);
            self.update_bottom_bar(rq, context);
        }
    }

    fn toggle_navigation_bar(
        &mut self,
        enable: Option<bool>,
        update: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let dpi = CURRENT_DEVICE.dpi;
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let (small_thickness, _) = halves(thickness);

        if let Some(index) = locate::<StackNavigationBar<DirectoryNavigationProvider>>(self) {
            if let Some(true) = enable {
                return;
            }

            let mut rect = *self.child(index).rect();
            rect.absorb(self.child(index + 1).rect());
            let delta_y = rect.height() as i32;

            // Remove the navigation bar and its separator.
            self.children.drain(index..=index + 1);
            self.shelf_index -= 2;
            context.settings.home.navigation_bar = false;

            // Move the shelf's top edge up.
            self.children[self.shelf_index].rect_mut().min.y -= delta_y;
        } else {
            if let Some(false) = enable {
                return;
            }

            let sep_index = if context.settings.home.address_bar {
                3
            } else {
                1
            };
            let sp_rect = *self.child(sep_index).rect() + pt!(0, small_height);

            let separator = Filler::new(sp_rect, BLACK);
            self.children
                .insert(sep_index + 1, Box::new(separator) as Box<dyn View>);

            let provider = DirectoryNavigationProvider;
            let mut nav_bar = StackNavigationBar::new(
                rect![
                    self.rect.min.x,
                    sp_rect.min.y - small_height + thickness,
                    self.rect.max.x,
                    sp_rect.min.y
                ],
                self.rect.max.y - small_height - big_height - small_thickness,
                context.settings.home.max_levels,
                provider,
                self.current_directory.clone(),
            );

            nav_bar.set_selected(self.current_directory.clone(), rq, context);
            self.children
                .insert(sep_index + 1, Box::new(nav_bar) as Box<dyn View>);

            self.shelf_index += 2;
            context.settings.home.navigation_bar = true;

            self.adjust_shelf_top_edge();
        }

        if update {
            for i in 2..self.shelf_index {
                rq.add(RenderData::new(
                    self.child(i).id(),
                    *self.child(i).rect(),
                    UpdateMode::Gui,
                ));
            }

            self.update_shelf(true, hub, rq, context);
            self.update_bottom_bar(rq, context);
        }
    }

    fn toggle_search_bar(
        &mut self,
        enable: Option<bool>,
        update: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        let dpi = CURRENT_DEVICE.dpi;
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let delta_y = small_height;
        let search_visible: bool;
        let mut has_keyboard = false;

        if let Some(index) = rlocate::<SearchBar>(self) {
            if let Some(true) = enable {
                return;
            }

            if let Some(ViewId::HomeSearchInput) = self.focus {
                self.toggle_keyboard(
                    false,
                    false,
                    Some(ViewId::HomeSearchInput),
                    hub,
                    rq,
                    context,
                );
            }

            // Remove the search bar and its separator.
            self.children.drain(index - 1..=index);

            // Move the shelf's bottom edge.
            self.children[self.shelf_index].rect_mut().max.y += delta_y;

            if context.settings.home.navigation_bar {
                let nav_bar = self.children[self.shelf_index - 2]
                    .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                    .unwrap();
                nav_bar.vertical_limit += delta_y;
            }

            self.query = None;
            search_visible = false;
        } else {
            if let Some(false) = enable {
                return;
            }

            let sp_rect = *self.child(self.shelf_index + 1).rect() - pt!(0, delta_y);
            let search_bar = SearchBar::new(
                rect![
                    self.rect.min.x,
                    sp_rect.max.y,
                    self.rect.max.x,
                    sp_rect.max.y + delta_y - thickness
                ],
                ViewId::HomeSearchInput,
                "Title, author, series",
                "",
                context,
            );
            self.children
                .insert(self.shelf_index + 1, Box::new(search_bar) as Box<dyn View>);

            let separator = Filler::new(sp_rect, BLACK);
            self.children
                .insert(self.shelf_index + 1, Box::new(separator) as Box<dyn View>);

            // Move the shelf's bottom edge.
            self.children[self.shelf_index].rect_mut().max.y -= delta_y;

            if context.settings.home.navigation_bar {
                let rect = *self.children[self.shelf_index].rect();
                let y_shift = rect.height() as i32 - (big_height - thickness);
                let nav_bar = self.children[self.shelf_index - 2]
                    .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                    .unwrap();
                nav_bar.vertical_limit -= delta_y;

                // Shrink the nav bar.
                if y_shift < 0 {
                    let y_shift = nav_bar.shrink(y_shift, &mut context.fonts);
                    self.children[self.shelf_index].rect_mut().min.y += y_shift;
                    *self.children[self.shelf_index - 1].rect_mut() += pt!(0, y_shift);
                }
            }

            if self.query.is_none() {
                if rlocate::<Keyboard>(self).is_none() {
                    self.toggle_keyboard(
                        true,
                        false,
                        Some(ViewId::HomeSearchInput),
                        hub,
                        rq,
                        context,
                    );
                    has_keyboard = true;
                }

                hub.send(Event::Focus(Some(ViewId::HomeSearchInput))).ok();
            }

            search_visible = true;
        }

        if update {
            if !search_visible {
                self.refresh_visibles(false, true, hub, rq, context);
            }

            self.update_top_bar(search_visible, rq);

            if search_visible {
                rq.add(RenderData::new(
                    self.child(self.shelf_index - 1).id(),
                    *self.child(self.shelf_index - 1).rect(),
                    UpdateMode::Partial,
                ));
                let mut rect = *self.child(self.shelf_index).rect();
                rect.max.y = self.child(self.shelf_index + 1).rect().min.y;
                // Render the part of the shelf that isn't covered.
                self.update_shelf(true, hub, &mut RenderQueue::new(), context);
                rq.add(RenderData::new(
                    self.child(self.shelf_index).id(),
                    rect,
                    UpdateMode::Partial,
                ));
                // Render the views on top of the shelf.
                rect.min.y = rect.max.y;
                let end_index = self.shelf_index + if has_keyboard { 4 } else { 2 };
                rect.max.y = self.child(end_index).rect().max.y;
                rq.add(RenderData::expose(rect, UpdateMode::Partial));
            } else {
                for i in self.shelf_index - 1..=self.shelf_index + 1 {
                    if i == self.shelf_index {
                        self.update_shelf(true, hub, rq, context);
                        continue;
                    }
                    rq.add(RenderData::new(
                        self.child(i).id(),
                        *self.child(i).rect(),
                        UpdateMode::Partial,
                    ));
                }
            }

            self.update_bottom_bar(rq, context);
        }
    }

    fn toggle_rename_document(
        &mut self,
        enable: Option<bool>,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if let Some(index) = locate_by_id(self, ViewId::RenameDocument) {
            if let Some(true) = enable {
                return;
            }
            self.target_document = None;
            rq.add(RenderData::expose(
                *self.child(index).rect(),
                UpdateMode::Gui,
            ));
            self.children.remove(index);
            if let Some(ViewId::RenameDocumentInput) = self.focus {
                self.toggle_keyboard(
                    false,
                    true,
                    Some(ViewId::RenameDocumentInput),
                    hub,
                    rq,
                    context,
                );
            }
        } else {
            if let Some(false) = enable {
                return;
            }
            let mut ren_doc = NamedInput::new(
                "Rename document".to_string(),
                ViewId::RenameDocument,
                ViewId::RenameDocumentInput,
                21,
                context,
            );
            if let Some(text) = self
                .target_document
                .as_ref()
                .and_then(|path| path.file_name())
                .and_then(|file_name| file_name.to_str())
            {
                ren_doc.set_text(text, rq, context);
            }
            rq.add(RenderData::new(
                ren_doc.id(),
                *ren_doc.rect(),
                UpdateMode::Gui,
            ));
            hub.send(Event::Focus(Some(ViewId::RenameDocumentInput)))
                .ok();
            self.children.push(Box::new(ren_doc) as Box<dyn View>);
        }
    }

    fn toggle_go_to_page(
        &mut self,
        enable: Option<bool>,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if let Some(index) = locate_by_id(self, ViewId::GoToPage) {
            if let Some(true) = enable {
                return;
            }
            rq.add(RenderData::expose(
                *self.child(index).rect(),
                UpdateMode::Gui,
            ));
            self.children.remove(index);
            if let Some(ViewId::GoToPageInput) = self.focus {
                self.toggle_keyboard(false, true, Some(ViewId::GoToPageInput), hub, rq, context);
            }
        } else {
            if let Some(false) = enable {
                return;
            }
            if self.pages_count < 2 {
                return;
            }
            let go_to_page = NamedInput::new(
                "Go to page".to_string(),
                ViewId::GoToPage,
                ViewId::GoToPageInput,
                4,
                context,
            );
            rq.add(RenderData::new(
                go_to_page.id(),
                *go_to_page.rect(),
                UpdateMode::Gui,
            ));
            hub.send(Event::Focus(Some(ViewId::GoToPageInput))).ok();
            self.children.push(Box::new(go_to_page) as Box<dyn View>);
        }
    }

    fn toggle_sort_menu(
        &mut self,
        rect: Rectangle,
        enable: Option<bool>,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if let Some(index) = locate_by_id(self, ViewId::SortMenu) {
            if let Some(true) = enable {
                return;
            }
            rq.add(RenderData::expose(
                *self.child(index).rect(),
                UpdateMode::Gui,
            ));
            self.children.remove(index);
        } else {
            if let Some(false) = enable {
                return;
            }
            let entries = vec![
                EntryKind::RadioButton(
                    "Date Opened".to_string(),
                    EntryId::Sort(SortMethod::Opened),
                    self.sort_method == SortMethod::Opened,
                ),
                EntryKind::RadioButton(
                    "Date Added".to_string(),
                    EntryId::Sort(SortMethod::Added),
                    self.sort_method == SortMethod::Added,
                ),
                EntryKind::RadioButton(
                    "Status".to_string(),
                    EntryId::Sort(SortMethod::Status),
                    self.sort_method == SortMethod::Status,
                ),
                EntryKind::RadioButton(
                    "Progress".to_string(),
                    EntryId::Sort(SortMethod::Progress),
                    self.sort_method == SortMethod::Progress,
                ),
                EntryKind::RadioButton(
                    "Author".to_string(),
                    EntryId::Sort(SortMethod::Author),
                    self.sort_method == SortMethod::Author,
                ),
                EntryKind::RadioButton(
                    "Title".to_string(),
                    EntryId::Sort(SortMethod::Title),
                    self.sort_method == SortMethod::Title,
                ),
                EntryKind::RadioButton(
                    "Year".to_string(),
                    EntryId::Sort(SortMethod::Year),
                    self.sort_method == SortMethod::Year,
                ),
                EntryKind::RadioButton(
                    "Series".to_string(),
                    EntryId::Sort(SortMethod::Series),
                    self.sort_method == SortMethod::Series,
                ),
                EntryKind::RadioButton(
                    "File Size".to_string(),
                    EntryId::Sort(SortMethod::Size),
                    self.sort_method == SortMethod::Size,
                ),
                EntryKind::RadioButton(
                    "File Type".to_string(),
                    EntryId::Sort(SortMethod::Kind),
                    self.sort_method == SortMethod::Kind,
                ),
                EntryKind::RadioButton(
                    "File Name".to_string(),
                    EntryId::Sort(SortMethod::FileName),
                    self.sort_method == SortMethod::FileName,
                ),
                EntryKind::RadioButton(
                    "File Path".to_string(),
                    EntryId::Sort(SortMethod::FilePath),
                    self.sort_method == SortMethod::FilePath,
                ),
                EntryKind::Separator,
                EntryKind::CheckBox(
                    "Reverse Order".to_string(),
                    EntryId::ReverseOrder,
                    self.reverse_order,
                ),
            ];
            let sort_menu = Menu::new(rect, ViewId::SortMenu, MenuKind::DropDown, entries, context);
            rq.add(RenderData::new(
                sort_menu.id(),
                *sort_menu.rect(),
                UpdateMode::Gui,
            ));
            self.children.push(Box::new(sort_menu) as Box<dyn View>);
        }
    }

    fn book_index(&self, index: usize) -> usize {
        let max_lines = self
            .child(self.shelf_index)
            .downcast_ref::<Shelf>()
            .unwrap()
            .max_lines;
        let index_lower = self.current_page * max_lines;
        (index_lower + index).min(self.visible_books.len())
    }

    fn toggle_book_menu(
        &mut self,
        index: usize,
        rect: Rectangle,
        enable: Option<bool>,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if let Some(index) = locate_by_id(self, ViewId::BookMenu) {
            if let Some(true) = enable {
                return;
            }
            rq.add(RenderData::expose(
                *self.child(index).rect(),
                UpdateMode::Gui,
            ));
            self.children.remove(index);
        } else {
            if let Some(false) = enable {
                return;
            }

            let book_index = self.book_index(index);
            let info = &self.visible_books[book_index];
            let path = &info.file.path;

            let mut entries = Vec::new();

            if let Some(parent) = path.parent() {
                entries.push(EntryKind::Command(
                    "Select Parent".to_string(),
                    EntryId::SelectDirectory(context.library.home.join(parent)),
                ));
            }

            if !info.author.is_empty() {
                entries.push(EntryKind::Command(
                    "Search Author".to_string(),
                    EntryId::SearchAuthor(info.author.clone()),
                ));
            }

            if !entries.is_empty() {
                entries.push(EntryKind::Separator);
            }

            let submenu: &[SimpleStatus] = match info.simple_status() {
                SimpleStatus::New => &[SimpleStatus::Reading, SimpleStatus::Finished],
                SimpleStatus::Reading => &[SimpleStatus::New, SimpleStatus::Finished],
                SimpleStatus::Finished => &[SimpleStatus::New, SimpleStatus::Reading],
            };

            let submenu = submenu
                .iter()
                .map(|s| EntryKind::Command(s.to_string(), EntryId::SetStatus(path.clone(), *s)))
                .collect();
            entries.push(EntryKind::SubMenu("Mark As".to_string(), submenu));
            entries.push(EntryKind::Separator);

            let selected_library = context.settings.selected_library;
            let libraries = context
                .settings
                .libraries
                .iter()
                .enumerate()
                .filter(|(index, _)| *index != selected_library)
                .map(|(index, lib)| (index, lib.name.clone()))
                .collect::<Vec<(usize, String)>>();
            if !libraries.is_empty() {
                let copy_to = libraries
                    .iter()
                    .map(|(index, name)| {
                        EntryKind::Command(name.clone(), EntryId::CopyTo(path.clone(), *index))
                    })
                    .collect::<Vec<EntryKind>>();
                let move_to = libraries
                    .iter()
                    .map(|(index, name)| {
                        EntryKind::Command(name.clone(), EntryId::MoveTo(path.clone(), *index))
                    })
                    .collect::<Vec<EntryKind>>();
                entries.push(EntryKind::SubMenu("Copy To".to_string(), copy_to));
                entries.push(EntryKind::SubMenu("Move To".to_string(), move_to));
            }

            entries.push(EntryKind::Command(
                "Rename".to_string(),
                EntryId::Rename(path.clone()),
            ));
            entries.push(EntryKind::Command(
                "Remove".to_string(),
                EntryId::Remove(path.clone()),
            ));

            let book_menu = Menu::new(
                rect,
                ViewId::BookMenu,
                MenuKind::Contextual,
                entries,
                context,
            );
            rq.add(RenderData::new(
                book_menu.id(),
                *book_menu.rect(),
                UpdateMode::Gui,
            ));
            self.children.push(Box::new(book_menu) as Box<dyn View>);
        }
    }

    fn toggle_library_menu(
        &mut self,
        rect: Rectangle,
        enable: Option<bool>,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if let Some(index) = locate_by_id(self, ViewId::LibraryMenu) {
            if let Some(true) = enable {
                return;
            }

            rq.add(RenderData::expose(
                *self.child(index).rect(),
                UpdateMode::Gui,
            ));
            self.children.remove(index);
        } else {
            if let Some(false) = enable {
                return;
            }

            let selected_library = context.settings.selected_library;
            let library_settings = &context.settings.libraries[selected_library];

            let libraries: Vec<EntryKind> = context
                .settings
                .libraries
                .iter()
                .enumerate()
                .map(|(index, lib)| {
                    EntryKind::RadioButton(
                        lib.name.clone(),
                        EntryId::LoadLibrary(index),
                        index == selected_library,
                    )
                })
                .collect();

            let database = if library_settings.mode == LibraryMode::Database {
                vec![
                    EntryKind::Command("Import".to_string(), EntryId::Import),
                    EntryKind::Command("Flush".to_string(), EntryId::Flush),
                ]
            } else {
                Vec::new()
            };

            let filesystem = if library_settings.mode == LibraryMode::Filesystem {
                vec![
                    EntryKind::CheckBox(
                        "Show Hidden".to_string(),
                        EntryId::ToggleShowHidden,
                        context.library.show_hidden,
                    ),
                    EntryKind::Separator,
                    EntryKind::Command("Clean Up".to_string(), EntryId::CleanUp),
                    EntryKind::Command("Flush".to_string(), EntryId::Flush),
                ]
            } else {
                Vec::new()
            };

            let mut entries = vec![EntryKind::SubMenu("Library".to_string(), libraries)];

            if !database.is_empty() {
                entries.push(EntryKind::SubMenu("Database".to_string(), database));
            }

            if !filesystem.is_empty() {
                entries.push(EntryKind::SubMenu("Filesystem".to_string(), filesystem));
            }

            let hooks: Vec<EntryKind> = context.settings.libraries[selected_library]
                .hooks
                .iter()
                .map(|v| {
                    EntryKind::Command(
                        v.path.to_string_lossy().into_owned(),
                        EntryId::ToggleSelectDirectory(context.library.home.join(&v.path)),
                    )
                })
                .collect();

            if !hooks.is_empty() {
                entries.push(EntryKind::SubMenu("Toggle Select".to_string(), hooks));
            }

            entries.push(EntryKind::Separator);

            let first_column = library_settings.first_column;
            entries.push(EntryKind::SubMenu(
                "First Column".to_string(),
                vec![
                    EntryKind::RadioButton(
                        "Title and Author".to_string(),
                        EntryId::FirstColumn(FirstColumn::TitleAndAuthor),
                        first_column == FirstColumn::TitleAndAuthor,
                    ),
                    EntryKind::RadioButton(
                        "File Name".to_string(),
                        EntryId::FirstColumn(FirstColumn::FileName),
                        first_column == FirstColumn::FileName,
                    ),
                ],
            ));

            let second_column = library_settings.second_column;
            entries.push(EntryKind::SubMenu(
                "Second Column".to_string(),
                vec![
                    EntryKind::RadioButton(
                        "Progress".to_string(),
                        EntryId::SecondColumn(SecondColumn::Progress),
                        second_column == SecondColumn::Progress,
                    ),
                    EntryKind::RadioButton(
                        "Year".to_string(),
                        EntryId::SecondColumn(SecondColumn::Year),
                        second_column == SecondColumn::Year,
                    ),
                ],
            ));

            entries.push(EntryKind::CheckBox(
                "Thumbnail Previews".to_string(),
                EntryId::ThumbnailPreviews,
                library_settings.thumbnail_previews,
            ));

            let trash_path = context.library.home.join(TRASH_DIRNAME);
            if let Ok(trash) = Library::new(trash_path, LibraryMode::Database)
                .map_err(|e| error!("Can't inspect trash: {:#?}.", e))
            {
                if trash.is_empty() == Some(false) {
                    entries.push(EntryKind::Separator);
                    entries.push(EntryKind::Command(
                        "Empty Trash".to_string(),
                        EntryId::EmptyTrash,
                    ));
                }
            }

            let library_menu = Menu::new(
                rect,
                ViewId::LibraryMenu,
                MenuKind::DropDown,
                entries,
                context,
            );
            rq.add(RenderData::new(
                library_menu.id(),
                *library_menu.rect(),
                UpdateMode::Gui,
            ));
            self.children.push(Box::new(library_menu) as Box<dyn View>);
        }
    }

    fn add_document(&mut self, info: Info, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        context.library.add_document(info);
        self.sort(false, hub, rq, context);
        self.refresh_visibles(true, false, hub, rq, context);
    }

    fn set_status(
        &mut self,
        path: &Path,
        status: SimpleStatus,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        context.library.set_status(path, status);

        // Is the current sort method affected by this change?
        if self.sort_method.is_status_related() {
            self.sort(false, hub, rq, context);
        }

        self.refresh_visibles(true, false, hub, rq, context);
    }

    fn empty_trash(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        let trash_path = context.library.home.join(TRASH_DIRNAME);

        let trash = Library::new(trash_path, LibraryMode::Database)
            .map_err(|e| error!("Can't load trash: {:#}.", e));
        if trash.is_err() {
            return;
        }

        let mut trash = trash.unwrap();

        let (files, _) = trash.list(&trash.home, None, false);
        if files.is_empty() {
            return;
        }

        let mut count = 0;
        for info in files {
            match trash.remove(&info.file.path) {
                Err(e) => error!("Can't erase {}: {:#}.", info.file.path.display(), e),
                Ok(()) => count += 1,
            }
        }
        trash.flush();
        let message = format!(
            "Removed {} book{}.",
            count,
            if count != 1 { "s" } else { "" }
        );
        let notif = Notification::new(None, message, false, hub, rq, context);
        self.children.push(Box::new(notif) as Box<dyn View>);
    }

    fn rename(
        &mut self,
        path: &Path,
        file_name: &str,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) -> Result<(), Error> {
        context.library.rename(path, file_name)?;
        self.refresh_visibles(true, false, hub, rq, context);
        Ok(())
    }

    fn remove(
        &mut self,
        path: &Path,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) -> Result<(), Error> {
        let full_path = context.library.home.join(path);
        if full_path.exists() {
            let trash_path = context.library.home.join(TRASH_DIRNAME);
            if !trash_path.is_dir() {
                fs::create_dir(&trash_path)?;
            }
            let mut trash = Library::new(trash_path, LibraryMode::Database)?;
            context.library.move_to(path, &mut trash)?;
            let (mut files, _) = trash.list(&trash.home, None, false);
            let mut size = files.iter().map(|info| info.file.size).sum::<u64>();
            if size > context.settings.home.max_trash_size {
                sort(&mut files, SortMethod::Added, true);
                while size > context.settings.home.max_trash_size {
                    let info = files.pop().unwrap();
                    if let Err(e) = trash.remove(&info.file.path) {
                        error!("Can't erase {}: {:#}", info.file.path.display(), e);
                        break;
                    }
                    size -= info.file.size;
                }
            }
            trash.flush();
        } else {
            context.library.remove(path)?;
        }
        self.refresh_visibles(true, false, hub, rq, context);
        Ok(())
    }

    fn copy_to(&mut self, path: &Path, index: usize, context: &mut Context) -> Result<(), Error> {
        let library_settings = &context.settings.libraries[index];
        let mut library = Library::new(&library_settings.path, library_settings.mode)?;
        context.library.copy_to(path, &mut library)?;
        library.flush();
        Ok(())
    }

    fn move_to(
        &mut self,
        path: &Path,
        index: usize,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) -> Result<(), Error> {
        let library_settings = &context.settings.libraries[index];
        let mut library = Library::new(&library_settings.path, library_settings.mode)?;
        context.library.move_to(path, &mut library)?;
        library.flush();
        self.refresh_visibles(true, false, hub, rq, context);
        Ok(())
    }

    fn set_reverse_order(
        &mut self,
        value: bool,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        self.reverse_order = value;
        self.current_page = 0;
        self.sort(true, hub, rq, context);
    }

    fn set_sort_method(
        &mut self,
        sort_method: SortMethod,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        self.sort_method = sort_method;
        self.reverse_order = sort_method.reverse_order();

        if let Some(index) = locate_by_id(self, ViewId::SortMenu) {
            self.child_mut(index)
                .children_mut()
                .last_mut()
                .unwrap()
                .downcast_mut::<MenuEntry>()
                .unwrap()
                .update(sort_method.reverse_order(), rq);
        }

        self.current_page = 0;
        self.sort(true, hub, rq, context);
    }

    fn sort(&mut self, update: bool, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        context.library.sort(self.sort_method, self.reverse_order);
        sort(
            &mut self.visible_books,
            self.sort_method,
            self.reverse_order,
        );

        if update {
            self.update_shelf(false, hub, rq, context);
            let search_visible = rlocate::<SearchBar>(self).is_some();
            self.update_top_bar(search_visible, rq);
            self.update_bottom_bar(rq, context);
        }
    }

    fn load_library(
        &mut self,
        index: usize,
        hub: &Hub,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) {
        if index == context.settings.selected_library {
            return;
        }

        let library_settings = context.settings.libraries[index].clone();
        let library = Library::new(&library_settings.path, library_settings.mode)
            .map_err(|e| error!("Can't load library: {:#}.", e));

        if library.is_err() {
            return;
        }

        let library = library.unwrap();

        let old_path = mem::take(&mut self.current_directory);
        self.terminate_fetchers(&old_path, false, hub, context);

        let mut update_top_bar = false;

        if self.query.is_some() {
            self.toggle_search_bar(Some(false), false, hub, rq, context);
            update_top_bar = true;
        }

        context.library.flush();

        context.library = library;
        context.settings.selected_library = index;

        if self.sort_method != library_settings.sort_method {
            self.sort_method = library_settings.sort_method;
            self.reverse_order = library_settings.sort_method.reverse_order();
            update_top_bar = true;
        }

        context.library.sort(self.sort_method, self.reverse_order);

        if update_top_bar {
            let search_visible = rlocate::<SearchBar>(self).is_some();
            self.update_top_bar(search_visible, rq);
        }

        if let Some(shelf) = self.children[self.shelf_index]
            .as_mut()
            .downcast_mut::<Shelf>()
        {
            shelf.set_first_column(library_settings.first_column);
            shelf.set_second_column(library_settings.second_column);
            shelf.set_thumbnail_previews(library_settings.thumbnail_previews);
        }

        let home = context.library.home.clone();
        self.select_directory(&home, hub, rq, context);
    }

    fn import(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        context.library.import(&context.settings.import);
        context.library.sort(self.sort_method, self.reverse_order);
        self.refresh_visibles(true, false, hub, rq, context);
    }

    fn clean_up(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        context.library.clean_up();
        self.refresh_visibles(true, false, hub, rq, context);
    }

    fn flush(&mut self, context: &mut Context) {
        context.library.flush();
    }

    fn terminate_fetchers(&mut self, path: &Path, update: bool, hub: &Hub, context: &mut Context) {
        self.background_fetchers.retain(|id, fetcher| {
            if fetcher.full_path == path {
                unsafe { libc::kill(*id as libc::pid_t, libc::SIGTERM) };
                fetcher.process.wait().ok();
                if update {
                    if let Some(sort_method) = fetcher.sort_method {
                        hub.send(Event::Select(EntryId::Sort(sort_method))).ok();
                    }
                    if let Some(first_column) = fetcher.first_column {
                        hub.send(Event::Select(EntryId::FirstColumn(first_column)))
                            .ok();
                    }
                    if let Some(second_column) = fetcher.second_column {
                        hub.send(Event::Select(EntryId::SecondColumn(second_column)))
                            .ok();
                    }
                } else {
                    let selected_library = context.settings.selected_library;
                    if let Some(sort_method) = fetcher.sort_method {
                        context.settings.libraries[selected_library].sort_method = sort_method;
                    }
                    if let Some(first_column) = fetcher.first_column {
                        context.settings.libraries[selected_library].first_column = first_column;
                    }
                    if let Some(second_column) = fetcher.second_column {
                        context.settings.libraries[selected_library].second_column = second_column;
                    }
                }
                false
            } else {
                true
            }
        });
    }

    fn insert_fetcher(&mut self, hook: &Hook, hub: &Hub, context: &Context) {
        let library_path = &context.library.home;
        let save_path = context.library.home.join(&hook.path);
        match self.spawn_child(
            library_path,
            &save_path,
            &hook.program,
            context.settings.wifi,
            context.online,
            hub,
        ) {
            Ok(process) => {
                let mut sort_method = hook.sort_method;
                let mut first_column = hook.first_column;
                let mut second_column = hook.second_column;
                if let Some(sort_method) = sort_method.replace(self.sort_method) {
                    hub.send(Event::Select(EntryId::Sort(sort_method))).ok();
                }
                let selected_library = context.settings.selected_library;
                if let Some(first_column) =
                    first_column.replace(context.settings.libraries[selected_library].first_column)
                {
                    hub.send(Event::Select(EntryId::FirstColumn(first_column)))
                        .ok();
                }
                if let Some(second_column) = second_column
                    .replace(context.settings.libraries[selected_library].second_column)
                {
                    hub.send(Event::Select(EntryId::SecondColumn(second_column)))
                        .ok();
                }
                self.background_fetchers.insert(
                    process.id(),
                    Fetcher {
                        path: hook.path.clone(),
                        full_path: save_path,
                        process,
                        sort_method,
                        first_column,
                        second_column,
                    },
                );
            }
            Err(e) => error!("Can't spawn child: {:#}.", e),
        }
    }

    fn spawn_child(
        &mut self,
        library_path: &Path,
        save_path: &Path,
        program: &Path,
        wifi: bool,
        online: bool,
        hub: &Hub,
    ) -> Result<Child, Error> {
        let path = program.canonicalize()?;
        let parent = path.parent().unwrap_or_else(|| Path::new(""));
        let mut process = Command::new(&path)
            .current_dir(parent)
            .arg(library_path)
            .arg(save_path)
            .arg(wifi.to_string())
            .arg(online.to_string())
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .spawn()?;
        let stdout = process
            .stdout
            .take()
            .ok_or_else(|| format_err!("can't take stdout"))?;
        let id = process.id();
        let hub2 = hub.clone();
        thread::spawn(move || {
            let reader = BufReader::new(stdout);
            for line_res in reader.lines() {
                if let Ok(line) = line_res {
                    if let Ok(event) = serde_json::from_str::<JsonValue>(&line) {
                        match event.get("type").and_then(JsonValue::as_str) {
                            Some("notify") => {
                                if let Some(msg) = event.get("message").and_then(JsonValue::as_str)
                                {
                                    hub2.send(Event::Notify(msg.to_string())).ok();
                                }
                            }
                            Some("setWifi") => {
                                if let Some(enable) =
                                    event.get("enable").and_then(JsonValue::as_bool)
                                {
                                    hub2.send(Event::SetWifi(enable)).ok();
                                }
                            }
                            Some("addDocument") => {
                                if let Some(info) = event
                                    .get("info")
                                    .map(ToString::to_string)
                                    .and_then(|v| serde_json::from_str(&v).ok())
                                {
                                    hub2.send(Event::FetcherAddDocument(id, Box::new(info)))
                                        .ok();
                                }
                            }
                            Some("removeDocument") => {
                                if let Some(path) = event.get("path").and_then(JsonValue::as_str) {
                                    hub2.send(Event::FetcherRemoveDocument(
                                        id,
                                        PathBuf::from(path),
                                    ))
                                    .ok();
                                }
                            }
                            Some("search") => {
                                let path = event
                                    .get("path")
                                    .and_then(JsonValue::as_str)
                                    .map(PathBuf::from);
                                let query = event
                                    .get("query")
                                    .and_then(JsonValue::as_str)
                                    .map(String::from);
                                let sort_by = event
                                    .get("sortBy")
                                    .map(ToString::to_string)
                                    .and_then(|v| serde_json::from_str(&v).ok());
                                hub2.send(Event::FetcherSearch {
                                    id,
                                    path,
                                    query,
                                    sort_by,
                                })
                                .ok();
                            }
                            _ => (),
                        }
                    }
                } else {
                    break;
                }
            }
            hub2.send(Event::CheckFetcher(id)).ok();
        });
        Ok(process)
    }

    fn reseed(&mut self, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        context.library.sort(self.sort_method, self.reverse_order);
        self.refresh_visibles(true, false, hub, &mut RenderQueue::new(), context);

        if let Some(top_bar) = self.child_mut(0).downcast_mut::<TopBar>() {
            top_bar.reseed(&mut RenderQueue::new(), context);
        }

        rq.add(RenderData::new(self.id, self.rect, UpdateMode::Gui));
    }
}

impl View for Home {
    #[cfg_attr(feature = "otel", tracing::instrument(skip(self, hub, _bus, rq, context), fields(event = ?evt), ret(level=tracing::Level::TRACE)))]
    fn handle_event(
        &mut self,
        evt: &Event,
        hub: &Hub,
        _bus: &mut Bus,
        rq: &mut RenderQueue,
        context: &mut Context,
    ) -> bool {
        match *evt {
            Event::Gesture(GestureEvent::Swipe {
                dir, start, end, ..
            }) => {
                match dir {
                    Dir::South
                        if self.children[0].rect().includes(start)
                            && self.children[self.shelf_index].rect().includes(end) =>
                    {
                        if !context.settings.home.navigation_bar {
                            self.toggle_navigation_bar(Some(true), true, hub, rq, context);
                        } else if !context.settings.home.address_bar {
                            self.toggle_address_bar(Some(true), true, hub, rq, context);
                        }
                    }
                    Dir::North
                        if self.children[self.shelf_index].rect().includes(start)
                            && self.children[0].rect().includes(end) =>
                    {
                        if context.settings.home.address_bar {
                            self.toggle_address_bar(Some(false), true, hub, rq, context);
                        } else if context.settings.home.navigation_bar {
                            self.toggle_navigation_bar(Some(false), true, hub, rq, context);
                        }
                    }
                    _ => (),
                }
                true
            }
            Event::Gesture(GestureEvent::Rotate { quarter_turns, .. }) if quarter_turns != 0 => {
                let (_, dir) = CURRENT_DEVICE.mirroring_scheme();
                let n = (4 + (context.display.rotation - dir * quarter_turns)) % 4;
                hub.send(Event::Select(EntryId::Rotate(n))).ok();
                true
            }
            Event::Gesture(GestureEvent::Arrow { dir, .. }) => {
                match dir {
                    Dir::West => self.go_to_page(0, hub, rq, context),
                    Dir::East => {
                        let pages_count = self.pages_count;
                        self.go_to_page(pages_count.saturating_sub(1), hub, rq, context);
                    }
                    Dir::North => {
                        let path = context.library.home.clone();
                        self.select_directory(&path, hub, rq, context);
                    }
                    Dir::South => self.toggle_search_bar(None, true, hub, rq, context),
                };
                true
            }
            Event::Gesture(GestureEvent::Corner { dir, .. }) => {
                match dir {
                    DiagDir::NorthWest | DiagDir::SouthWest => {
                        self.go_to_status_change(CycleDir::Previous, hub, rq, context)
                    }
                    DiagDir::NorthEast | DiagDir::SouthEast => {
                        self.go_to_status_change(CycleDir::Next, hub, rq, context)
                    }
                };
                true
            }
            Event::Focus(v) => {
                if self.focus != v {
                    self.focus = v;
                    if v.is_some() {
                        self.toggle_keyboard(true, true, v, hub, rq, context);
                    }
                }
                true
            }
            Event::Show(ViewId::Keyboard) => {
                self.toggle_keyboard(true, true, None, hub, rq, context);
                true
            }
            Event::Toggle(ViewId::GoToPage) => {
                self.toggle_go_to_page(None, hub, rq, context);
                true
            }
            Event::Toggle(ViewId::SearchBar) => {
                self.toggle_search_bar(None, true, hub, rq, context);
                true
            }
            Event::ToggleNear(ViewId::TitleMenu, rect) => {
                self.toggle_sort_menu(rect, None, rq, context);
                true
            }
            Event::ToggleBookMenu(rect, index) => {
                self.toggle_book_menu(index, rect, None, rq, context);
                true
            }
            Event::ToggleNear(ViewId::MainMenu, rect) => {
                toggle_main_menu(self, rect, None, rq, context);
                true
            }
            Event::ToggleNear(ViewId::BatteryMenu, rect) => {
                toggle_battery_menu(self, rect, None, rq, context);
                true
            }
            Event::ToggleNear(ViewId::ClockMenu, rect) => {
                toggle_clock_menu(self, rect, None, rq, context);
                true
            }
            Event::ToggleNear(ViewId::LibraryMenu, rect) => {
                self.toggle_library_menu(rect, None, rq, context);
                true
            }
            Event::Close(ViewId::AddressBar) => {
                self.toggle_address_bar(Some(false), true, hub, rq, context);
                true
            }
            Event::Close(ViewId::SearchBar) => {
                self.toggle_search_bar(Some(false), true, hub, rq, context);
                true
            }
            Event::Close(ViewId::SortMenu) => {
                self.toggle_sort_menu(Rectangle::default(), Some(false), rq, context);
                true
            }
            Event::Close(ViewId::LibraryMenu) => {
                self.toggle_library_menu(Rectangle::default(), Some(false), rq, context);
                true
            }
            Event::Close(ViewId::MainMenu) => {
                toggle_main_menu(self, Rectangle::default(), Some(false), rq, context);
                true
            }
            Event::Close(ViewId::GoToPage) => {
                self.toggle_go_to_page(Some(false), hub, rq, context);
                true
            }
            Event::Close(ViewId::RenameDocument) => {
                self.toggle_rename_document(Some(false), hub, rq, context);
                true
            }
            Event::Select(EntryId::Sort(sort_method)) => {
                let selected_library = context.settings.selected_library;
                context.settings.libraries[selected_library].sort_method = sort_method;
                self.set_sort_method(sort_method, hub, rq, context);
                true
            }
            Event::Select(EntryId::ReverseOrder) => {
                let next_value = !self.reverse_order;
                self.set_reverse_order(next_value, hub, rq, context);
                true
            }
            Event::Select(EntryId::LoadLibrary(index)) => {
                self.load_library(index, hub, rq, context);
                true
            }
            Event::Select(EntryId::Import) => {
                self.import(hub, rq, context);
                true
            }
            Event::Select(EntryId::CleanUp) => {
                self.clean_up(hub, rq, context);
                true
            }
            Event::Select(EntryId::Flush) => {
                self.flush(context);
                true
            }
            Event::FetcherAddDocument(_, ref info) => {
                self.add_document(*info.clone(), hub, rq, context);
                true
            }
            Event::Select(EntryId::SetStatus(ref path, status)) => {
                self.set_status(path, status, hub, rq, context);
                true
            }
            Event::Select(EntryId::FirstColumn(first_column)) => {
                let selected_library = context.settings.selected_library;
                context.settings.libraries[selected_library].first_column = first_column;
                self.update_first_column(hub, rq, context);
                true
            }
            Event::Select(EntryId::SecondColumn(second_column)) => {
                let selected_library = context.settings.selected_library;
                context.settings.libraries[selected_library].second_column = second_column;
                self.update_second_column(hub, rq, context);
                true
            }
            Event::Select(EntryId::ThumbnailPreviews) => {
                let selected_library = context.settings.selected_library;
                context.settings.libraries[selected_library].thumbnail_previews =
                    !context.settings.libraries[selected_library].thumbnail_previews;
                self.update_thumbnail_previews(hub, rq, context);
                true
            }
            Event::Submit(ViewId::AddressBarInput, ref addr) => {
                self.toggle_keyboard(false, true, None, hub, rq, context);
                self.select_directory(Path::new(addr), hub, rq, context);
                true
            }
            Event::Submit(ViewId::HomeSearchInput, ref text) => {
                self.query = BookQuery::new(text);
                if self.query.is_some() {
                    self.toggle_keyboard(false, false, None, hub, rq, context);
                    // Render the search bar and its separator.
                    for i in self.shelf_index + 1..=self.shelf_index + 2 {
                        rq.add(RenderData::new(
                            self.child(i).id(),
                            *self.child(i).rect(),
                            UpdateMode::Gui,
                        ));
                    }
                    self.refresh_visibles(true, true, hub, rq, context);
                } else {
                    let notif = Notification::new(
                        None,
                        "Invalid search query.".to_string(),
                        false,
                        hub,
                        rq,
                        context,
                    );
                    self.children.push(Box::new(notif) as Box<dyn View>);
                }
                true
            }
            Event::Submit(ViewId::GoToPageInput, ref text) => {
                if text == "(" {
                    self.go_to_page(0, hub, rq, context);
                } else if text == ")" {
                    self.go_to_page(self.pages_count.saturating_sub(1), hub, rq, context);
                } else if text == "_" {
                    let index = (context.rng.next_u64() % self.pages_count as u64) as usize;
                    self.go_to_page(index, hub, rq, context);
                } else if let Ok(index) = text.parse::<usize>() {
                    self.go_to_page(index.saturating_sub(1), hub, rq, context);
                }
                true
            }
            Event::Submit(ViewId::RenameDocumentInput, ref file_name) => {
                if let Some(ref path) = self.target_document.take() {
                    self.rename(path, file_name, hub, rq, context)
                        .map_err(|e| error!("Can't rename document: {:#}.", e))
                        .ok();
                }
                true
            }
            Event::NavigationBarResized(_) => {
                self.adjust_shelf_top_edge();
                self.update_shelf(true, hub, rq, context);
                self.update_bottom_bar(rq, context);
                for i in self.shelf_index - 2..=self.shelf_index - 1 {
                    rq.add(RenderData::new(
                        self.child(i).id(),
                        *self.child(i).rect(),
                        UpdateMode::Gui,
                    ));
                }
                true
            }
            Event::Select(EntryId::EmptyTrash) => {
                self.empty_trash(hub, rq, context);
                true
            }
            Event::Select(EntryId::Rename(ref path)) => {
                self.target_document = Some(path.clone());
                self.toggle_rename_document(Some(true), hub, rq, context);
                true
            }
            Event::Select(EntryId::Remove(ref path))
            | Event::FetcherRemoveDocument(_, ref path) => {
                self.remove(path, hub, rq, context)
                    .map_err(|e| error!("Can't remove document: {:#}.", e))
                    .ok();
                true
            }
            Event::Select(EntryId::CopyTo(ref path, index)) => {
                self.copy_to(path, index, context)
                    .map_err(|e| error!("Can't copy document: {:#}.", e))
                    .ok();
                true
            }
            Event::Select(EntryId::MoveTo(ref path, index)) => {
                self.move_to(path, index, hub, rq, context)
                    .map_err(|e| error!("Can't move document: {:#}.", e))
                    .ok();
                true
            }
            Event::Select(EntryId::ToggleShowHidden) => {
                context.library.show_hidden = !context.library.show_hidden;
                self.refresh_visibles(true, false, hub, rq, context);
                true
            }
            Event::SelectDirectory(ref path)
            | Event::Select(EntryId::SelectDirectory(ref path)) => {
                self.select_directory(path, hub, rq, context);
                true
            }
            Event::ToggleSelectDirectory(ref path)
            | Event::Select(EntryId::ToggleSelectDirectory(ref path)) => {
                self.toggle_select_directory(path, hub, rq, context);
                true
            }
            Event::Select(EntryId::SearchAuthor(ref author)) => {
                let text = format!("'a {}", author);
                let query = BookQuery::new(&text);
                if query.is_some() {
                    self.query = query;
                    self.toggle_search_bar(Some(true), false, hub, rq, context);
                    self.toggle_keyboard(false, false, None, hub, rq, context);
                    if let Some(search_bar) =
                        self.children[self.shelf_index + 2].downcast_mut::<SearchBar>()
                    {
                        search_bar.set_text(&text, rq, context);
                    }
                    // Render the search bar and its separator.
                    for i in self.shelf_index + 1..=self.shelf_index + 2 {
                        rq.add(RenderData::new(
                            self.child(i).id(),
                            *self.child(i).rect(),
                            UpdateMode::Gui,
                        ));
                    }
                    self.refresh_visibles(true, true, hub, rq, context);
                }
                true
            }
            Event::GoTo(location) => {
                self.go_to_page(location as usize, hub, rq, context);
                true
            }
            Event::Chapter(dir) => {
                let pages_count = self.pages_count;
                match dir {
                    CycleDir::Previous => self.go_to_page(0, hub, rq, context),
                    CycleDir::Next => {
                        self.go_to_page(pages_count.saturating_sub(1), hub, rq, context)
                    }
                }
                true
            }
            Event::Page(dir) => {
                self.go_to_neighbor(dir, hub, rq, context);
                true
            }
            Event::Device(DeviceEvent::Button {
                code: ButtonCode::Backward,
                status: ButtonStatus::Pressed,
                ..
            }) => {
                self.go_to_neighbor(CycleDir::Previous, hub, rq, context);
                true
            }
            Event::Device(DeviceEvent::Button {
                code: ButtonCode::Forward,
                status: ButtonStatus::Pressed,
                ..
            }) => {
                self.go_to_neighbor(CycleDir::Next, hub, rq, context);
                true
            }
            Event::Device(DeviceEvent::NetUp) => {
                for fetcher in self.background_fetchers.values_mut() {
                    if let Some(stdin) = fetcher.process.stdin.as_mut() {
                        writeln!(stdin, "{}", json!({"type": "network", "status": "up"})).ok();
                    }
                }
                true
            }
            Event::FetcherSearch {
                id,
                ref path,
                ref query,
                ref sort_by,
            } => {
                let path = path.as_ref().unwrap_or(&context.library.home);
                let query = query.as_ref().and_then(|text| BookQuery::new(text));
                let (mut files, _) = context.library.list(path, query.as_ref(), false);
                if let Some((sort_method, reverse_order)) = *sort_by {
                    sort(&mut files, sort_method, reverse_order);
                }
                for entry in &mut files {
                    // Let the *reader* field pass through.
                    mem::swap(&mut entry.reader, &mut entry.reader_info);
                }
                if let Some(fetcher) = self.background_fetchers.get_mut(&id) {
                    if let Some(stdin) = fetcher.process.stdin.as_mut() {
                        writeln!(
                            stdin,
                            "{}",
                            json!({"type": "search",
                                                     "results": files})
                        )
                        .ok();
                    }
                }
                true
            }
            Event::CheckFetcher(id) => {
                if let Some(fetcher) = self.background_fetchers.get_mut(&id) {
                    if let Ok(exit_status) = fetcher.process.wait() {
                        if !exit_status.success() {
                            let msg = format!(
                                "{}: abnormal process termination.",
                                fetcher.path.display()
                            );
                            let notif = Notification::new(None, msg, false, hub, rq, context);
                            self.children.push(Box::new(notif) as Box<dyn View>);
                        }
                    }
                }
                true
            }
            Event::ToggleFrontlight => {
                if let Some(index) = locate::<TopBar>(self) {
                    self.child_mut(index)
                        .downcast_mut::<TopBar>()
                        .unwrap()
                        .update_frontlight_icon(rq, context);
                }
                true
            }
            Event::Reseed => {
                self.reseed(hub, rq, context);
                true
            }
            _ => false,
        }
    }

    #[cfg_attr(feature = "otel", tracing::instrument(skip(self, _fb, _fonts, _rect), fields(rect = ?_rect)))]
    fn render(&self, _fb: &mut dyn Framebuffer, _rect: Rectangle, _fonts: &mut Fonts) {}

    fn resize(&mut self, rect: Rectangle, hub: &Hub, rq: &mut RenderQueue, context: &mut Context) {
        let dpi = CURRENT_DEVICE.dpi;
        let thickness = scale_by_dpi(THICKNESS_MEDIUM, dpi) as i32;
        let (small_thickness, big_thickness) = halves(thickness);
        let (small_height, big_height) = (
            scale_by_dpi(SMALL_BAR_HEIGHT, dpi) as i32,
            scale_by_dpi(BIG_BAR_HEIGHT, dpi) as i32,
        );

        self.children.retain(|child| !child.is::<Menu>());

        // Top bar.
        let top_bar_rect = rect![
            rect.min.x,
            rect.min.y,
            rect.max.x,
            rect.min.y + small_height - small_thickness
        ];
        self.children[0].resize(top_bar_rect, hub, rq, context);

        let separator_rect = rect![
            rect.min.x,
            rect.min.y + small_height - small_thickness,
            rect.max.x,
            rect.min.y + small_height + big_thickness
        ];
        self.children[1].resize(separator_rect, hub, rq, context);

        let mut shelf_min_y = rect.min.y + small_height + big_thickness;
        let mut index = 2;

        // Address bar.
        if context.settings.home.address_bar {
            self.children[index].resize(
                rect![
                    rect.min.x,
                    shelf_min_y,
                    rect.max.x,
                    shelf_min_y + small_height - thickness
                ],
                hub,
                rq,
                context,
            );
            shelf_min_y += small_height - thickness;
            index += 1;

            self.children[index].resize(
                rect![rect.min.x, shelf_min_y, rect.max.x, shelf_min_y + thickness],
                hub,
                rq,
                context,
            );
            shelf_min_y += thickness;
            index += 1;
        }

        // Navigation bar.
        if context.settings.home.navigation_bar {
            let count = if self.children[self.shelf_index + 2].is::<SearchBar>() {
                2
            } else {
                1
            };
            let nav_bar = self.children[index]
                .as_mut()
                .downcast_mut::<StackNavigationBar<DirectoryNavigationProvider>>()
                .unwrap();
            nav_bar.clear();
            nav_bar.resize(
                rect![
                    rect.min.x,
                    shelf_min_y,
                    rect.max.x,
                    shelf_min_y + small_height - thickness
                ],
                hub,
                rq,
                context,
            );
            nav_bar.vertical_limit =
                rect.max.y - count * small_height - big_height - small_thickness;
            nav_bar.set_selected(
                self.current_directory.clone(),
                &mut RenderQueue::new(),
                context,
            );
            shelf_min_y += nav_bar.rect().height() as i32;
            index += 1;

            self.children[index].resize(
                rect![rect.min.x, shelf_min_y, rect.max.x, shelf_min_y + thickness],
                hub,
                rq,
                context,
            );
            shelf_min_y += thickness;
        }

        // Bottom bar.
        let bottom_bar_index = rlocate::<BottomBar>(self).unwrap();
        index = bottom_bar_index;

        let separator_rect = rect![
            rect.min.x,
            rect.max.y - small_height - small_thickness,
            rect.max.x,
            rect.max.y - small_height + big_thickness
        ];
        self.children[index - 1].resize(separator_rect, hub, rq, context);

        let bottom_bar_rect = rect![
            rect.min.x,
            rect.max.y - small_height + big_thickness,
            rect.max.x,
            rect.max.y
        ];
        self.children[index].resize(bottom_bar_rect, hub, rq, context);

        let mut shelf_max_y = rect.max.y - small_height - small_thickness;

        if index - self.shelf_index > 2 {
            index -= 2;
            // Keyboard.
            if self.children[index].is::<Keyboard>() {
                let kb_rect = rect![
                    rect.min.x,
                    rect.max.y - (small_height + 3 * big_height) as i32 + big_thickness,
                    rect.max.x,
                    rect.max.y - small_height - small_thickness
                ];
                self.children[index].resize(kb_rect, hub, rq, context);
                let s_max_y = self.children[index].rect().min.y;
                self.children[index - 1].resize(
                    rect![rect.min.x, s_max_y - thickness, rect.max.x, s_max_y],
                    hub,
                    rq,
                    context,
                );
                index -= 2;
            }
            // Search bar.
            if self.children[index].is::<SearchBar>() {
                let sp_rect = *self.children[index + 1].rect() - pt!(0, small_height);
                self.children[index].resize(
                    rect![
                        rect.min.x,
                        sp_rect.max.y,
                        rect.max.x,
                        sp_rect.max.y + small_height - thickness
                    ],
                    hub,
                    rq,
                    context,
                );
                self.children[index - 1].resize(sp_rect, hub, rq, context);
                shelf_max_y -= small_height;
            }
        }

        // Shelf.
        let shelf_rect = rect![rect.min.x, shelf_min_y, rect.max.x, shelf_max_y];
        self.children[self.shelf_index].resize(shelf_rect, hub, rq, context);

        self.update_shelf(true, hub, &mut RenderQueue::new(), context);
        self.update_bottom_bar(&mut RenderQueue::new(), context);

        // Floating windows.
        for i in bottom_bar_index + 1..self.children.len() {
            self.children[i].resize(rect, hub, rq, context);
        }

        self.rect = rect;
        rq.add(RenderData::new(self.id, self.rect, UpdateMode::Full));
    }

    fn rect(&self) -> &Rectangle {
        &self.rect
    }

    fn rect_mut(&mut self) -> &mut Rectangle {
        &mut self.rect
    }

    fn children(&self) -> &Vec<Box<dyn View>> {
        &self.children
    }

    fn children_mut(&mut self) -> &mut Vec<Box<dyn View>> {
        &mut self.children
    }

    fn id(&self) -> Id {
        self.id
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::battery::{Battery, FakeBattery};
    use crate::framebuffer::Pixmap;
    use crate::frontlight::{Frontlight, LightLevels};
    use crate::lightsensor::LightSensor;
    use std::env;
    use std::path::Path;

    fn create_test_context() -> Context {
        let fb = Box::new(Pixmap::new(600, 800, 1)) as Box<dyn Framebuffer>;
        let battery = Box::new(FakeBattery::new()) as Box<dyn Battery>;
        let frontlight = Box::new(LightLevels::default()) as Box<dyn Frontlight>;
        let lightsensor = Box::new(0u16) as Box<dyn LightSensor>;

        let fonts = crate::font::Fonts::load_from(
            Path::new(
                &env::var("TEST_ROOT_DIR").expect("TEST_ROOT_DIR must be set for this test."),
            )
            .to_path_buf(),
        )
        .expect(
            "Failed to load fonts. Tests require font files to be present. \
             Run tests from the project root directory.",
        );

        Context::new(
            fb,
            None,
            crate::library::Library::new(Path::new("/tmp"), crate::settings::LibraryMode::Database)
                .unwrap(),
            crate::settings::Settings::default(),
            fonts,
            battery,
            frontlight,
            lightsensor,
        )
    }

    #[test]
    fn test_toggle_address_bar_with_navigation_bar_maintains_separator_alignment() {
        let mut context = create_test_context();
        let (tx, _rx) = std::sync::mpsc::channel();
        let hub = tx;
        let mut rq = RenderQueue::new();

        context.settings.home.navigation_bar = false;
        context.settings.home.address_bar = false;

        let rect = rect![0, 0, 600, 800];
        let mut home = Home::new(rect, &hub, &mut rq, &mut context).unwrap();

        home.toggle_navigation_bar(Some(true), false, &hub, &mut rq, &mut context);
        assert!(context.settings.home.navigation_bar);

        let nav_bar_index =
            locate::<StackNavigationBar<DirectoryNavigationProvider>>(&home).unwrap();
        let separator_index = home.shelf_index - 1;

        let nav_bar_bottom_before = home.children[nav_bar_index].rect().max.y;
        let separator_top_before = home.children[separator_index].rect().min.y;
        assert_eq!(
            nav_bar_bottom_before, separator_top_before,
            "Navigation bar and separator should be aligned before toggling address bar"
        );

        home.toggle_address_bar(Some(true), false, &hub, &mut rq, &mut context);
        assert!(context.settings.home.address_bar);

        let nav_bar_index =
            locate::<StackNavigationBar<DirectoryNavigationProvider>>(&home).unwrap();
        let separator_index = home.shelf_index - 1;

        let nav_bar_bottom_after_enable = home.children[nav_bar_index].rect().max.y;
        let separator_top_after_enable = home.children[separator_index].rect().min.y;
        assert_eq!(
            nav_bar_bottom_after_enable, separator_top_after_enable,
            "Navigation bar and separator should remain aligned after enabling address bar"
        );

        home.toggle_address_bar(Some(false), false, &hub, &mut rq, &mut context);
        assert!(!context.settings.home.address_bar);

        let nav_bar_index =
            locate::<StackNavigationBar<DirectoryNavigationProvider>>(&home).unwrap();
        let separator_index = home.shelf_index - 1;

        let nav_bar_bottom_after_disable = home.children[nav_bar_index].rect().max.y;
        let separator_top_after_disable = home.children[separator_index].rect().min.y;
        assert_eq!(
            nav_bar_bottom_after_disable, separator_top_after_disable,
            "Navigation bar and separator should remain aligned after disabling address bar"
        );
    }
}